A wheel clamp, also known as wheel boot, parking boot, or Denver boot,[1][2] is a device that is designed to prevent vehicles from being moved. In its most common form, it consists of a clamp that surrounds a vehicle wheel, designed to prevent removal of both itself and the wheel.

In the United States, these devices became known as a "Denver boot" after the city of Denver, Colorado was the first in the country to employ them, mostly to force the payment of outstanding parking tickets.[3]

The wheel clamp, originally known as the auto immobiliser, was invented in 1944 and patented in 1958 by Frank Marugg.[4] Marugg was a pattern maker, a violinist with the Denver Symphony Orchestra, and a good friend to many Denver politicians and police department officials. The police department needed a solution to a growing parking enforcement problem. The city used to tow all ticketed cars to the pound, where they were often vandalised. Those who were ticketed sued the city for the damage and the police had to itemise everything in the cars. Dan Stills, a policeman, thought an immobiliser would avoid the expensive towing problem and approached Marugg with an idea on how to immobilise a vehicle.

The Denver police first used the wheel boot on 5 January 1955 and collected over US$18,000 (US$158,467 in 2015 dollars[5]) in its first month of use. Although the wheel boot was first cast in steel, Marugg soon switched to a lighter aluminum-based alloy. Marugg later sold the device to parking lot owners, hotels and ski resorts, as well as a Jumbo version for farm equipment and larger vehicles. The Smithsonian Institution now has a copy of Marugg's boot on display in Washington, D.C.[6][7]

The most infamous wheel clamp in the UK is the 'London Wheel Clamp'. The designer, Trevor Whitehouse and patent owner of device number GB2251416A filed the patent in 1991. He originally called the device the 'Preston' based on his home town in Lancashire. Primarily used on private land, its notoriety grew once it was introduced to public roads under the Road Traffic Regulations Act of 1991. (Commonly known as the de-criminalising of the yellow lines act.) The first areas in the country to be decriminalised were the 33 London Boroughs during 1993/94, hence the name change.

Wheel-clamping is notoriously unpopular with unauthorised parkers. Whereas a traffic warden or police officer has jurisdiction over public roads, in many countries, the law allows landowners to wheel clamp vehicles parking on their property without permission.

One British man became so annoyed at having his car clamped that he removed the clamp with an angle grinder. He subsequently received publicity as a self-styled "superhero" called “Angle-Grinder Man”, offering to remove clamps for free with his angle grinder.[8]

Other motorists have taken the action of cutting the clamps off with bolt cutters or even clamping their own cars beforehand so that property owners will be unable to clamp an already-clamped vehicle and may think that another owner has clamped it. However, the practice of removing clamps is usually only done for those that were installed by firms and other citizens; the removal of clamps installed by authorities (chiefly the police) is an offence.[citation needed]

A New Zealand wheel clamper made national headlines in 2013 after he secretly recorded a police officer allegedly threatening to not help if an aggrieved member of the public attacked him.[9] It was not the first time the clamper involved had been in the news.[10]

In Scotland, local authorities are permitted by statute to clamp, tow, or otherwise remove vehicles. Outside that statutory authority, clamping on private land was found to be unlawful in the case Black v Carmichael (1992) SCCR 709, which held that immobilising a vehicle constitutes extortion and theft. Writing in dismissal of parking contractor Alan Black's appeal to the High Court of Justiciary, the Lord Justice General (Lord Hope) cited case law which said "every man has a right to dispute the demand of his creditor in a court of justice" and himself wrote "it is illegal for vehicles to be held to ransom in the manner described in these charges".[11]

In England and Wales, The Protection of Freedoms Act 2012 criminalised certain wheel-clamping activity on private land without lawful authority from 1 October 2012. This prohibits clamping in many common locations such as supermarket car parks, but clamping is not entirely banned. For example, a railway operator may clamp a vehicle under the provisions of Railway Byelaw 14(4).[12]

Despite it being illegal for private operators to immobilise vehicles with these types of devices in the U.S. State of Washington, the practice continues.[13][14] In February 2013 charges were laid against a private parking operator, along with the property owner, in the city of Los Angeles for attaching wheel clamps to vehicles in a privately owned parking lot.[15][16]

In the Republic of Ireland, private clamping of cars not owned by the property owner is illegal under Section 113 the Road Traffic Act 1961[17] as amended by the Road Traffic Act (Amendment) 1984[18][original research?]. However, it is still extremely common as the arcane language of these provisions is beyond many.[citation needed]